


Epilogue (Cage of Thorns)

by Spaceelf



Category: Fire Emblem Series, Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: F/M, Fluff, Fluff and Smut, Kissing, Romance, Secret Relationship, Smut, Vaginal Sex, Wedding Night, no beta we die like Glenn, other characters are minor appearances, secret engagement
Language: English
Status: Completed
Published: 2020-08-15
Updated: 2020-08-15
Packaged: 2021-03-06 08:00:10
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,584
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25909996
Author URL: https://archiveofourown.org/users/Spaceelf/pseuds/Spaceelf
Summary: Byleth and Seteth decide to make their secret relationship not-so-secret.They end up fucking.(Takes place after the events in my Cage of Thorns fic.)
Relationships: My Unit | Byleth/Seteth
Comments: 7
Kudos: 56





	Epilogue (Cage of Thorns)

**Author's Note:**

> Based on a wonderful prompt suggested on Cage of Thorns! While I did end the fic, I decided that the engagement antics and wedding night would be best as it's own standalone since I was satisfied with the ending of Cage of Thorns. But u can have this little extra Setleth as a treat.
> 
> Smut smut smut smut smut just a smutty single thingy smut smut smut

At long last their work restoring Fodlan finished. Byleth, as ruler of Fodlan, could at last rest and enjoy more of her time as she wished. Her duties as ruler fell into a routine, and while minor issues arose, the routine itself became a sign she was truly finished.

Seteth, as archbishop, worked tirelessly for the church and at Byleth’s side as her right hand. As their workload eased, he found more opportunities to steal away with her, even with a still relatively strict schedule. They continued to keep their relationship a secret, fearing the controversy and arguments over favoritism that might arise even with their work so freshly completed. Finally discrediting the rumors after being caught by a maid just before the war’s end had taken serious work, and quite a few public arguments. Indeed those public arguments turned to private sins. Sins that Seteth indulged in, despite not too long ago shunning the idea.

“You work so well together,” Catherine observed them one day. Seteth leaned in next to Byleth to point something out in the report before her. “One would almost think you didn’t completely hate each other’s guts.”

Byleth snorted. Of course she felt the heat radiating from the man next to her. She longed to be closer to him. But the world wasn’t quite ready.

“Pay no need to those comments, your majesty. We have much bigger problems at hand.” Seteth muttered, continuing to guide Byleth through the reports. Catherine and others stood by, awaiting their decision for the Knights’ next objective.

Whispers about their chemistry were nothing new. Byleth and Seteth opted shortly after their confessions to hide their rings away until they were ready. When the Knights cleared from the room, Seteth slid his hands over Byleth’s shoulders.

“How much longer will we have to hide this?” He whispered.

“Things are going smoothly now, I’ve considered it for some time.” Byleth mulled over the idea for the thousandth time. “Maybe we should mess with them, first.”  
Seteth cocked an eyebrow as she met his gaze with a smirk. “What do you mean?”  
“We could just shock them. Get into a spat and end it by swapping spit.” Her crass language never really fell out of use with her new title. It was endearing in a way. “Catch them by surprise.”

“I was thinking more along the lines of starting to wear the rings, and maybe dismissing it and avoiding the comments until someone figured it out.” Seteth suggested. “Though your idea seems much more enticing. But we can’t get carried away. We wouldn’t want to end up in some risque situation at an odd location.”  
“And why not? We fucked in the stables that one time.”

“Byleth!” He blushed, “Please.”  
“Well, what about that time in the confessional?” She rose from her seat to close the already narrow distance between them.

“Honestly, I don’t know what to do with you!”  
“And your desk?”

“Byleth!” He snapped.

She leaned up and kissed him, her tongue parting his lips. He gasped but reciprocated, his hands sliding from her shoulders down to her ass. “Why don’t you come to my room tonight?”  
“You know that’s risky now that there isn’t a war going on and no excuse to keep me working late. Flayn will be setting out to be on her own in some time.” He objected.

“Wouldn’t you rather have her present for the wedding?”  
“W-Wedding?”  
“We could start planning now…” Her fingers played with the buttons of his robes.

Seteth’s heart fluttered. “I--”  
The door burst open, the stablemaster running in. Instantly Byleth and Seteth turned away from each other. The Stablemaster blurted about the still very young but very large wyvern pups roaming into the dining hall. Seteth turned to Byleth and frowned.

“What? They were hungry this morning!” She shrugged. “I thought they could follow me in for an early breakfast when no one was around.”

“And you left them  _ out _ ?”

“They were sleepy afterwards.”  
“And then they came wandering back in since you led them in the first time!” Seteth groaned, his palm colliding with his face. “I will deal with you later.” He hissed, glaring at her before following the Stablemaster out.

Byleth slumped back into her chair, pouting.

\---

Byleth found herself training late that evening. The workout turned more into stress relief. The training grounds were dark and deserted, and did not see as much use as they did during the war. Tired, she sighed and returned her training sword to the rack before taking a moment to catch her breath. She leaned against the wall under the eaves of the perimeter, sighing.

“I thought I might find you here.” Seteth’s voice startled her. He emerged from the shadows, his arms folded. “It took me all day to wrangle those wyverns.”  
“Maybe if they were fed properly they’d be easier to handle.” She scoffed.

“They are fed properly! Feeding them cakes is not a part of their diet!” Seteth huffed.

“Lighten up, they deserve to have a treat every now and then!” She waved to dismiss him.

He did the opposite, slamming his hands against the wall on either side of her. “It was very frustrating having to clean up your mess again.” His voice a low rumble.

“Oh?” She smirked.

He leaned in, kissing her, his hands seizing her arms to still her. When they broke, she was breathless. His eyes darkened.

“You know we are all alone here.” She purred.

“I am very aware.” He growled, his hand already trailing up under her shirt to knead her breast. He flicked his thumb over her nipple, she shuddered and whined. He kissed her to silence her, his other hand dipping into the front of her shorts, fingers sliding down between her folds to greet the wet slick waiting for him. He made a noise of approval upon feeling her readiness, and swirled his fingers around her clit. She writhed under his grip, moans muffled by his tongue.

Her hands brushed against the bulge in his pants. His hips bucked into it, cueing her to unfasten his trousers and free his hard length. He dripped precum as she stroked him and squeezed his balls gently. His movements became more rushed, pulling her shirt up to completely expose her breasts, and yanking her shorts down for easy access.

He cupped her breasts as she fondled him. Seteth leaned down and took turns sucking at each nipple, drawing needy moans from her. He positioned himself so his cock grinded between her thighs, rubbing against her slick folds. He pulled up one of her legs, and she steadied herself by clutching his shoulders before he impaled her with a forceful thrust.

She whimpered, burying her face into his chest as he pushed into her so she was pressed into the wall, the force able to support her as he fucked her slow and hard. Even after confessing their feelings for one another, they still found ways to frustrate each other, though it was lighthearted enough.

His grunts evolved into a crescendo of moans with each pump, joining hers in a chorus. She cried out and tensed, cumming over him as he increased his pace and slipped a hand down to rub her clit. Release found her as she drenched him, shuddering. He stilled inside her for a moment to allow her to come down from her high, kissing her neck. She panted, clutching him tightly, meeting his piercing gaze.

“I’m not through with you.” He growled. She quivered and smiled as he eased her down, steadying her in his arms as her legs wobbled from little aftershocks. They kissed until she felt steady.

“I’m ready.” She mewled. He spun her around, bending her over and pushing her hands against the wall. Seteth rutted his cock against her ass, and she pressed into him. She glanced over her shoulder at him, and he was spurred to shealth himself in her immediately.

He shuddered, his hands clawing down her arms and back to knead into her ass as he made pace. He panted, the need to make her cum again blurring with his own desperate chase for release. He felt sweat trickle down his back, dampening his robes. This wasn’t the first time they soiled his clothing.

Unholy sounds tore from his throat as he reached up and grabbed a fistful of her hair, pulling her head back. Her back arched into it as she moaned from the sensation, pressing herself into his thrusts further. Her pussy quivered over his cock, warning him of her approaching orgasm. Desperate to cum himself, he pounded into her, finding release at last when she tightened and convulsed over him. He filled her with his hot seed, fluids leaking from between them as he clutched her, buried inside as he savored his high.

The sound of footsteps snapped him back to reality. Someone was running… away. His heart sank.

“Someone may have seen us.” He whispered, pulling her upright and pressing her against the wall to shield her. He scanned the training grounds over his shoulder, but there was no sign of anyone.

“Are you sure?” Byleth gasped.

“I… don’t know.” He furrowed his brow, stepping back to allow her to dress. He shoved his cock back into his trousers and hurriedly fastened them. “It’s later than I anticipated. I should go.”  
She grabbed his hand, “I love you.” She pressed a kiss to his lips, and he leaned into it. His hands brushed through her hair.

\---

Byleth glanced around, seeing that the coast was clear before she slipped out of the training grounds. Halfway across the walkway, she heard a laugh and froze. She whirled around to see Catherine slip out of the shadows.

“Out for some late night training?” Catherine chuckled.

Byleth turned bright red. “Well yes.”  
“Funny, I just saw Seteth leave…” She grinned. “Training together?”

Byleth nodded.

“That didn’t look like training to me.”  
Byleth gasped. “You! You _saw_ us?”

“Maybe you shouldn’t get too comfortable fucking in public places.” Catherine snickered. “Even if you think you’re the only ones around.” Byleth turned bright red. “Of course, I’m more interested to know how  _ you two  _ of all people ended up doing such  _ lewd  _ acts.”

“I don’t know what you’re talking about.” She huffed.

“Oh don’t play stupid with me, your majesty.” Catherine chuckled. “Seteth is too stuffy for me to confront but you wear your heart on your sleeve.” Byleth hung her head in shame. “Honestly, I could cut the tension between you two with a knife. Everyone’s dying to hear news like this. Was that rumor true, too?”

“I will not even dignify that with a response!” Byleth snarled.

“That long, huh?” Catherine folded her arms. “You two were like  _ animals _ .”

“No one will believe you.” Byleth hissed.

“Is that so?” Catherine sneered, “The chemistry between you two speaks for itself. Regardless of if I tell or not, it’s only a matter of time.”

Byleth cursed under her breath, clenching her fists. “Fine, whatever.” She stormed back to the Royal Suite.

\---

Byleth made her way down the halls, doing her morning rounds around the monastery. Seteth took the time to join her, nonchalant. He folded his arms behind his back, the picture of perfect posture. In contrast, she was tense and it was evident.

“Something the matter?” He asked in a hushed tone. They passed a crowd and found themselves alone as they turned into another corridor.

“We were seen last night. Your suspicions were correct.” She grumbled.

“Do you know whom?”  
“Catherine. No one else.”  
“I suppose we will see if another rumor spreads, then.” He sighed.

“Wouldn’t you rather just announce it?”

“I am not ready.”  
“You still haven’t talked to Flayn about it?” Byleth asked, keeping her gaze forward.

“I… have not.” His step faltered with the reply, but they continued on.

“I suppose when you are ready, then.” Byleth said. “I will be patient, for you my love.”

“Thank you.” She could hear the smile in his voice as they continued their walk, moving the subject to business.

\---

“Brother, I was so surprised when you invited me for afternoon tea. You are usually so busy these days!” Flayn greeted, gliding into Seteth’s office.

Seteth grinned and hugged her, closing the door behind her. “Flayn, I must have a very serious conversation with you.”  
“Oh? Is something wrong?” Flayn sat across from him at his desk, watching as he poured tea.

“You are aware that Byleth knows about us.” Seteth stated flatly. Flayn nodded. “Well, I was wondering, do you like her?”

“Of course! Her majesty is quite amazing. I can leave here knowing that Fodlan is in good hands.” Flayn beamed.

“Flayn…” Seteth was wounded by her words. “How soon do you wish to leave?”  
“Within the next year. I wanted to talk to you about this, Father.” She switched her tone, addressing him properly. “I have grown much, and with the threats against us now gone, I think it is time I finally leave the nest.”  
“I see.” He hesitated for a moment, “I have done much to try and shelter you from the world. I believe it is also time for me to move forward.”  
“Whatever do you mean?”  
“I rather like her majesty.” He put it delicately.

“You are courting her?” Flayn gasped. “But I thought you were at odds!”

“You could say that. I have been courting her for quite some time now. But I did not know how you would react.”  
“Aha! This is wonderful news. I am thrilled!” Flayn clapped.

“You are not upset with me?”

“Of course not.”

“Would you please keep this a secret for now, Cethleann?” Seteth whispered.

Flayn nodded. “I should like to see you wed before I depart.”

“In less than a year?” It was his turn to be incredulous.

“Hurry up! I would like a little sister.”

“F-Flayn!”

\---

It seemed that Catherine only let the detail slip to a few people, as Byleth wasn’t pestered nearly as much as when the previous rumor got out. While she refused to humor the eager questions, focusing on her meal, she didn’t notice Seteth parting the crowd to speak to her.

“Your majesty.” Seteth addressed formally. Her attention snapped up to him, her mouth full of food. She cocked an eyebrow. He glared down his nose at the small crowd around them, who watched with anticipation. “I have addressed the matter you spoke to me earlier about.”

It took Byleth a moment. “Flayn?”  
Seteth nodded, with a slight bow. “It is done.”

Deciding to be bold, she finished her meal and got to her feet, looking him over. “Well then. My quarters, tonight.”

Seteth’s face turned bright red as he sputtered a response. While the crowd around them had absolutely no context, they still began to whisper. Their assumptions, of course, were correct. With a smug grin, Byleth strutted back to her office.

\---

Of course, Seteth trusted Byleth. He was not one to be trifled with. His stride was all business, as he passed the monastery staff, the guards, and the maids up to Byleth’s room. He caught them staring from the corner of his eye, some of them slack-jawed. He cleared his throat and knocked on her door, wary that the maids were spying on him from down the hall.

Byleth called to him, “Who is it?”  
Seteth straightened himself, “You wanted to see me, your majesty?”  
“Come in.”  
He opened the door and closed it behind him, “Surely this is strictly business from how you commented so plainly about--” He looked up to see her lounging naked on her bed, waiting for him. His face turned bright red. “Byleth, we can’t--” He hissed.

“Might as well.” She shrugged. “Come on, let everyone gossip. You told Flayn, right?”  
His face grew to a deeper shade of red, “She is elated. And demanding a younger sibling.”

“Well that might have to wait a bit, but I’m sure we can certainly practice.” Byleth purred, patting her bedspread.

“Byleth! We can’t just--”  
She pouted, sitting up. Her hair fell over her shoulder, her arms propped herself up and pressed her breasts together. He came undone at the vision, his breath hitching.

His voice cracked, “Well I suppose.” He was quick to disrobe, crossing her chambers in only a few great strides, bounding into her bed. He lay down next to her, hovering his hand over the contour of her hip, hesitant. “There’s no point in hiding anymore, is there?”

She leaned down to kiss him, “They can figure it out for themselves.” He sighed, suddenly relieved that he would not have to hide his affections any longer.

She straddled him, grinding her wet cunt over his cock. “Excited already?” He crooned. She chuckled and nibbled his ear, sending a jolt through him. His hands slid up her thighs to clutch her plush ass. He leaned up to suck at her nipples, enticing her to grind against him harder.

His cock throbbed, aching to feel her. As if to read his thoughts, Byleth lifted herself and took hold of his shaft, angling it just right. She slid over it with a sigh, resting over him for a moment. He hummed, palming her breasts and meeting her gaze.

She steadied herself before grinding into a pace, enjoying a leisurely ride over him. A long groan escaped his lips. Byleth’s hands splayed over his chest, occasionally brushing his nipples. The sensation made him writhe in pleasure, as if he could have melted under her. Seteth’s eyes fluttered shut as he let the feeling take over.

He soon felt himself bucking his hips up into her, unable to resist. His hands clutched her hips, helping her rhythm increase. Byleth’s movements soon became erratic as she struggled to contain herself. Seteth was eager to see her cum. To his dismay, she pulled herself free from him, moving away to catch her breath.

“I don’t want to cum just yet.” She panted.

Seteth sat up on his knees, “Whenever you’re ready.” He fisted his cock, enjoying the view of her flushed face and heaving breasts.

Byleth embraced him, sliding over him and turning to grind her ass against his cock. She reached up and tangled her fingers into his hair, pulling him into a kiss. His hands trailed around her to pinch her nipples, pulling a moan from her. Her ass tilted upward and she spread her knees apart, grinding her hot cunt against his length.

She was horny and desperate to make this last, but riding Seteth had brought her so very close so quickly, she wasn’t sure she would last much longer. Seteth grew impatient, and pulled her backwards, sliding her onto his shaft with a shaky moan. He nuzzled into the back of her neck and kissed her shoulder as he grabbed her wrists and pulled them backwards.

A strong thrust had her seeing stars as he hit the perfect spot, taking her by surprise. She trembled as he pulled her back once more and thrust again. A loud moan escaped her, louder than her previous sounds. There was no way the maids in the hallway didn’t hear her. But the sensation of how he fucked her, hitting that perfect spot had her senses completely blind to anything beyond him.

The sounds she made only encouraged him, pushing him to a fervent pace and his own edge. He was enamored with her sounds, and the feel of her plush ass against him as he pounded into her at the perfect angle. He growled through gritted teeth, his eyes dark and savage as he rode the edge.

He pulled her back like drawing a bowstring, taut and tightening. He twitched, and after a few more thrusts he found release, spilling inside her with hard, deep thrusts. Those final thrusts were enough to send her over the edge, as she gasped his name, drenching him. She flopped backwards into his embrace, pulling free of him, leaking their spend over the sheets.

They caught their breath between sweet kisses. In their amorous haze, they drifted asleep.

\---

When morning came, the maids brought breakfast as expected. Seteth opened a single sleepy eye to see them whispering by the door, dropping the breakfast tray on the parlor table before scurrying back out. Byleth was sound asleep in his arms as he spooned her.

He smiled and hummed, amused by the scandal he just allowed to happen. While they were covered by the duvet, it was still very evident that he and Byleth were both naked, and if they hadn’t heard the loud cries of ecstasy last night, the vision of them together would have reassured the fact that they had intercourse. Pleased with himself, Seteth allowed for a chance to sleep in. After all, he wasn’t particularly overwhelmed with his work, and he wouldn’t want to disappoint the ruler of Fodlan by leaving her to greet the day alone.

It felt right to be by her side. Not just in their work and daily efforts, but intimately and in her bed. This was where he wanted to be. Where he needed to be. Where he would always be.

Some time later, Byleth stirred, rolling over to meet him with a smile. “You’re here.”

He grinned, kissing her. “Always.” He nodded toward the breakfast tray across the chamber, “The maids brought your breakfast.”  
“So they saw you.”  
“They saw _us_.” He corrected.

She chuckled, “Good. I can’t wait to hear their reactions.”  
“Perhaps we should be a little more public with our affections?” He purred, kissing her neck. “Just to see their shock.”  
“Certainly.” She gave a wry smile.

\---

Throughout the day they watched jaws drop as they expressed their affections in subtle ways. Seteth, instead of standing next to Byleth to point out details on reports, loomed behind her, reaching around her to make notes while he hooked his chin over her shoulder, speaking softly. Byleth, in turn, would brush his arm during discussions or when they strolled the monastery together.

They relished every gasp, every stunned expression of the people of Garreg Mach. Catherine seemed rather pleased with herself. And while people expressed their surprise, no one directly asked them about their relationship.

Flayn seemed delighted that Seteth spent the night with Byleth, and insisted he should move in with her. Apprehensive himself, Seteth was surprised Byleth was eager to support such an idea.

“After all, we have been seeing one another for… quite some time.” Byleth blushed.

Flayn was on the edge of her seat, her eyes glued to Seteth as he mulled over a decision. “Very well. I suppose this will help me adjust to the idea of you leaving, Flayn.”

  
  


\---

As Byleth and Seteth held audience one day to receive open concerns and issues, Manuela slinked up to them, “So are you two… together?”

Byleth grinned, and Seteth nodded.

“No!” She gasped, incredulous. “I had heard word, but hardly believed it. You two hated each other. What caused the change of heart?”

“Actually…” Byleth squeaked out, “We’ve been keeping it secret for quite some time.”

Manuela’s eye grew wide, “And you just decide to start acting all warm and fuzzy out of the blue?”

“Well, with things sorted out, we would like to get married.” Seteth admitted, loud enough so everyone in the audience chamber could hear. He clasped Byleth’s hand in his.

The buzz that followed brought with it a wave of questions and surprise, along with congratulations.

\---

The wedding was simple, with friends and dignitaries from near and far in attendance. The reception was lighthearted and filled with food and dancing well into the night. Byleth and Seteth finally stole away from the celebration to consummate their union in the Royal Suite, which had been adorned with roses and rose petals.

Seteth looked at her with yearning eyes, that longing expression he had so many times before… before they confessed, before the war ended, before…

It didn’t matter. Now, he was in her room… No,  _ their  _ room. Together. Though he made his vow to her long before that day, saying it before the world and affirming it invigorated him. A new beginning, where he, the Archbishop, would not only support the Ruler of Fodlan in their work, but in all other aspects of their life.

His hands here gentle, soft. Leisurely he roamed over her, disrobing her. Byleth was more impatient, peeling away his clothes with enthusiasm. Their kisses were tender, their embrace tight, as if they couldn’t get close enough, desperate for touch.

Seteth laid her down in the silken sheets, parting from her lips only to regard her for a moment. Beautiful, adoring. His.

Her eyes told the same story. He was strong, handsome, hers.

He eased down next to her, and she rolled over top of him. Their kisses long and sensual. Byleth’s hands moved for Seteth first, working his shaft and balls. He hardened in her grasp, his breath hitching as his pupils dilated with lust. From the excitement of the wedding to this very moment, something inside him stirred.

Heat boiled in Byleth’s core, and she couldn’t get enough of Seteth. Touching him, kissing him. Still, she moved with patience and gentleness. He moved his fingers down to her lower lips, drawing her slick from her entrance out over her folds and up to her sensitive bud.

She sighed as he teased her, until she hooked her leg over him and moved into position. He drew his fingers away, moving his hand over her side to hold her close and tight. There was only the sound of their heavy breaths.

Byleth eased forward over him. Filling her was ecstasy. Seteth resisted the urge to lose himself, to have his eyes roll backward. His focus was on her in utter adoration. She leaned forward, capturing his lips. They didn’t break away from each other as they both moved in time with one another, feeling every inch of pleasure, relishing every second.

Slow, passionate, their bodies coiled, moving every imaginable way for hour upon hour, with stamina unlike ever before. Seteth sucked at her nipples, leaning up, then moving slowly to keep her impaled on him as he laid her on her back, and began to work once more at giving her everything he possibly could. His mind, his body, his soul.

She wanted him to take every bit of her: her flesh, her essence, her heart. She would make the exchange a thousand times over just to be with him, to hold him as she was, to feel him as she did. He filled all of her, his body formed to her so completely, a perfect match.

Byleth never wanted anything more than this beautiful green-haired saint that worshipped her with every move, leaving her gasping and shaking as she came again and again.

Seteth knew that this night would be theirs. Yet he would have her every night for centuries to come, and every time it would feel like their first, most passionate, most sensual night. He would make it so. She praised him with every sigh, every time her fingers clutched his back or tangled into his hair, every time her back arched.

Again and again, they found each other. Release sweet, endless. Their orgasmic haze blurred into a loving sleep. Entangled in the sheets, their hands clasped together in an embrace, they found a blissful peace that would remain forever more.


End file.
